[Evaluation of the quality of Gastrodia elata Bl. by HPLC-DAD/MS]

The chromatographic fingerprint of Gastrodia elata Bl. (Tianma) was developed to compare the quality of Tianma samples from different habitats and processing methods. The above analysis method was established by HPLC-DAD technique. And an HPLC method was used to analysis the contents of gastrodin (GAS) and p-hydroxybenzyl alcohol (HBA) in Tianma from different habitats and processed methods. Experiments of chromatographic fingerprint analysis were carried out with a Zorbax XDB C18 column (250 mm x 4.6 mm, 5 microm). The mobile phase consisted of acetonitrile and 0.1% aqueous acetic acid in gradient elution mode. The column was maintained at 25 degrees C. Detection was set at 270 nm. The mass spectra were recorded using as ESI source in the negative mode with ion spray voltage at 3500 V, source temperature at 335 degrees C, gas spray at 8.3 kPa and gas flow rate at 9 L x min(-1). The HPLC methods of quantitative analysis were the same as those of chromatographic fingerprint analysis except the mobile phase, which consisted of acetonitrile and 0.1% aqueous acetic acid in isocratic elution mode with the ratio of 4.5 to 95.5 (v/v). Data of chromatographic fingerprint were analyzed by the "similarity evaluation system for chromatographic fingerprint of TCM (Version 2004 A)" software to compare the quality of Tianma. Samples from different habitats with the same processing method were of high similarity, though a few samples showed evident difference in fingerprint graphics. For Tianma samples with different processing methods, the contents of common peaks were different and the processing method of freezing to dry was better than others. With HPLC-MS technique, 8 major common peaks in the fingerprint of Tianma were identified by their MS spectra and comparison with the reference standards. The results of similarity analysis for chromatographic fingerprint were basically consistent with those of quantitative analysis. The established HPLC-DAD/MS methods can be used to evaluate the quality of Tianma.